From owner-freebsd-fs@freebsd.org Thu Oct 10 15:39:45 2019 Return-Path: Delivered-To: freebsd-fs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 5460B141F98; Thu, 10 Oct 2019 15:39:45 +0000 (UTC) (envelope-from kib@freebsd.org) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 46pwJ04sc8z4Fhk; Thu, 10 Oct 2019 15:39:44 +0000 (UTC) (envelope-from kib@freebsd.org) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id x9AFdXhp011691 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Thu, 10 Oct 2019 18:39:36 +0300 (EEST) (envelope-from kib@freebsd.org) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua x9AFdXhp011691 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id x9AFdWbZ011690; Thu, 10 Oct 2019 18:39:32 +0300 (EEST) (envelope-from kib@freebsd.org) X-Authentication-Warning: tom.home: kostik set sender to kib@freebsd.org using -f Date: Thu, 10 Oct 2019 18:39:32 +0300 From: Konstantin Belousov To: Zhichao1.Li@dell.com Cc: freebsd-fs@freebsd.org, freebsd-drivers@freebsd.org, Shunchao.Hu@dell.com Subject: Re: a issue about getting a devfs node's fullpath Message-ID: <20191010153932.GO44691@kib.kiev.ua> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tom.home X-Rspamd-Queue-Id: 46pwJ04sc8z4Fhk X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-1.79 / 15.00]; local_wl_from(0.00)[freebsd.org]; NEURAL_HAM_MEDIUM(-0.79)[-0.795,0]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; NEURAL_HAM_LONG(-1.00)[-0.998,0] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Oct 2019 15:39:45 -0000 On Thu, Oct 10, 2019 at 05:49:55AM +0000, Zhichao1.Li@dell.com wrote: > Dear freebsd developers > I know you're swamped, so I'll be brief. > I am trying to get a node's full under /dev by calling the function 'vn_fullpath', when dealing with things like '/dev/null' or '/dev/usb/1.0.1', it works well. > However when dealing a node under more than 2 sub directories (e.g. /dev/bus/usb/001/002) which I made by calling 'make_dev_s' , it goes a little bit different, I got a string "/dev/bus/usb/bus/usb/001/002" > And I found the function 'devfs_vptocnp' gets the string wrongly when dealing multi slashes path string, I have remark the code as followed and put some comments > would you please take a look, and tell me what the purpose this func pass the string that way? Try this. Not tested. diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c index 3b80c68e309..f20b466d88b 100644 --- a/sys/fs/devfs/devfs_vnops.c +++ b/sys/fs/devfs/devfs_vnops.c @@ -284,38 +284,27 @@ devfs_vptocnp(struct vop_vptocnp_args *ap) if (error != 0) return (error); - i = *buflen; + if (vp->v_type != VCHR && vp->v_type != VDIR) { + error = ENOENT; + goto finished; + } + dd = vp->v_data; + if (vp->v_type == VDIR && dd == dmp->dm_rootdir) { + *dvp = vp; + vref(*dvp); + goto finished; + } - if (vp->v_type == VCHR) { - i -= strlen(dd->de_cdp->cdp_c.si_name); - if (i < 0) { - error = ENOMEM; - goto finished; - } - bcopy(dd->de_cdp->cdp_c.si_name, buf + i, - strlen(dd->de_cdp->cdp_c.si_name)); - de = dd->de_dir; - } else if (vp->v_type == VDIR) { - if (dd == dmp->dm_rootdir) { - *dvp = vp; - vref(*dvp); - goto finished; - } - i -= dd->de_dirent->d_namlen; - if (i < 0) { - error = ENOMEM; - goto finished; - } - bcopy(dd->de_dirent->d_name, buf + i, - dd->de_dirent->d_namlen); - de = dd; - } else { - error = ENOENT; + i = *buflen; + i -= dd->de_dirent->d_namlen; + if (i < 0) { + error = ENOMEM; goto finished; } + bcopy(dd->de_dirent->d_name, buf + i, dd->de_dirent->d_namlen); *buflen = i; - de = devfs_parent_dirent(de); + de = devfs_parent_dirent(dd); if (de == NULL) { error = ENOENT; goto finished;